Grid-tied energy storage systems play an increasing role in providing stabilization and security to the nation's energy transmission grid. These systems assist integration of the increasing number of renewable energy sources into the grid by allowing storage of excess energy during peak production times and delivery when needed. They allow electric utilities to increase system performance, reliability and security, smooth integration of renewable energy production, and delay building new peak demand capacity. Industrial users can also realize benefits from grid-tied storage systems for uninterruptible power supplies and economical time-of-use pricing.